In one form of vacuum cleaner, a suction nozzle is moved over the floor surface by means of a wand connected to the nozzle and a handle mounted to the upper end of the wand and connected through a hose to the suction unit of the vacuum cleaner, such as the canister portion thereof.
In one form of such vacuum cleaner, electrical power is provided to a brush motor mounted in the nozzle, through electrical conductors extending along the wand. The upper end of the wand conductors is provided with an electrical connector adapted to be removably connected to a complementary connector mounted to the handle. Electrical conductors are connected to the connector of the handle and extend through the hose to be electrically connected to the electrical power supply at a connection at the suction unit.
The present invention is concerned with means for mounting the electrical connector to the upper end of the wand.
One such electrical connector is illustrated in U.S. Pat. No. 4,422,702 of Irwin E. Nordeen, which patent is owned by the assignee hereof. As shown therein, the electrical connector comprises a plug having projecting male terminals adapted to be removably received in electrical connected association with the female plug 24 mounted to the handle of the suction hose. A plug housing is mounted to the wand and includes a base portion secured to the wand upper end, such as by rivets. The female connector is secured to the hose handle portion by a second housing.
Recently, microprocessor controls have been incorporated in the handle of such vacuum cleaner structures providing improved control of the operation of the vacuum cleaner. It has been found, however, that at times, false control signals are generated by the static electricity which builds up as a result of the flow of the soil particles through the wand and hose assembly. It has been found that such an electrostatic charge may, at times, reach a potential which is high enough to cause an electrostatic discharge, thereby providing spurious operation of the microprocessor control. A number of solutions to this vexatious problem have been attempted, but none has proven completely satisfactory. It has been found impractical and substantially not possible to eliminate the buildup of the static charge. Similarly, attempts to provide an increased insulation of the wire leads, so that the breakdown resistance exceeds the electrostatic charge potential, has been found to be impractical. This approach tends to cause the charge voltage to increase, thus exposing the user to a higher potential and, thus, would be undesirable.
Another solution has been to provide a static shield mounted to the plug retainer to prevent discharge of the electrostatic charge to the electrical conductors. The static shield devices of the prior art have not proven completely satisfactory, in that the electrostatic charges have discharged around the shield between the shield and retainer element.